Cameras having extended depth-f-field (EDOF) lenses can capture images having objects at both near and far distances from the camera, where the objects remain in focus. A property of an EDOF camera is that the optics design implements a particular tradeoff among its parameters (described below), and subsequent signal processing must take into account this trade-off in order to obtain good quality images having the extended depth of field effect. The optics, imaging sensor, and signal processing module constitute an EDOF imaging system.
The EDOF lens optics are designed such that a tradeoff is made between the peak-sharpness of the EDOF lens, and the invariance of the optical point spread functions (PSFs) of the lens with the distance to an object in a scene. A PSF is an array of numbers that describe the quality and quantity of blurring of a received image at each point of a scene. The manifestation of this trade-off is that the EDOF camera system, while achieving a greater depth of field, also has PSFs in a range around best focus, that are broader compared to a conventional lens PSF at best focus.
Accordingly, there is a need and desire for an extended depth-of-field (EDOF) imaging system that can account for the trade-off between peak sharpness and extended depth-of-field to recover focus in recaptured images.